The present invention relates to a method for manufacturing a stator including a substrate for connection to coils, an apparatus for manufacturing a stator, and a stator.
A conventional motor includes coils wound around an annular stator core. Each coil includes a winding-initiating ends and winding-terminating end that form lead lines, which are drawn out from one axial end of the stator core. The lead lines are electrically connected to, for example, a substrate arranged on one axial side of the stator core. The substrate electrically connects predetermined ones of the coils. Further, the coils are supplied with excitation current through the substrate.
Japanese Laid-Open Patent Publication No. 06-233505 describes an example of a method for manufacturing such a stator including a substrate. The method uses L-shaped pins to connect lead lines of coils to a substrate arranged at one axial side of the stator core. The stator core includes radially extending teeth and is covered by an insulator. Pins are arranged on one axial end of the insulator. Each pin includes a distal portion, or horizontal portion, extending toward the inner side of the stator core along the radial direction of the stator core. When coils are wound around the teeth from above the insulator by a nozzle of a coil winder, the nozzle winds the lead lines of the coils around the horizontal portions of the pins. After the substrate is set between the horizontal portions and the stator core at one axial side of the stator core, the pins are driven into the insulators to firmly join the horizontal portions with the substrate. Then, the horizontal portions and the lead lines wound around the horizontal portions are soldered to electrically connect the horizontal portions, the lead lines wound around the horizontal portions, and a printed wiring formed on the substrate. This electrically connects the lead lines to the substrate.
However, when the lead lines are connected to the substrate by implementing the method described in the above publication, the task for arranging the pins on the insulator is difficult. Further, the nozzle of the coil winder required to be moved to wind the lead lines around the horizontal portions of the pins. Thus, the movement of the nozzle is complicated. For example, since there are a variety of wire connection patterns, for example, the coils may be wound around the corresponding teeth into a concentrated winding while connecting the lead lines at the winding-initiating and winding-terminating ends of each coil to the substrate. In this case, a large number of lead lines, which is two times the number of the coils, are wound around the horizontal portions of the pins. This lowers the manufacturing efficiency of the stator.